assert failed. cond="m_dcBit == DATA_PDU"

Some 5G-LENA users have recently reported the following issue:

assert failed. cond="m_dcBit == DATA_PDU", +4.543099995s 73 file=/ns-3-dev/src/lte/model/lte-pdcp-header.cc, line=114
terminate called without an active exception

I open this issue to gather here all the information to find the cause and solve it. In order to start solving the issue we need:

• the example script with which we could reproduce this issue. The example should be simple, with just a few gNBs and UEs.
• any information that you might gather by doing your own investigation and debugging related to this script

5G-LENA users questions:

1. https://groups.google.com/g/5g-lena-users/c/n3aHOYhUUMU/m/OQqTs-blAgAJ
2. https://groups.google.com/g/5g-lena-users/c/ULoVrOlvLYw/m/41vLDiUSBAAJ

Past related issues:

1. https://groups.google.com/g/ns-3-users/c/4W5GAty99oI